Question

10-29. Determine , which locates the centroidal axis ' for the cross-sectional area of the T-beam, and then find the moments of inertiaI and Ly 5 mm 75 mm 150 mm

Answer 1

Given figure Finding the centroid of the T - beam y = y_1 A_1 + y_2 A_2 /A_1 + A_2 y = 100 times [150 times 20] + 75 times [150 times 20]/150 times 20 + 150 times 20 = 117.5 so, y = (150 + 20) - 117.5 = 52.5mm I_x' = I_x_1 + I_x_2 = 150 times 20^/12 + (150 times 20) times 52.5^2 + 20 times 150^3/12 + (150 times 20) times 42.5^2 I_x' = 19.41 times 10^6 mm^4 I_y' = I_y_1 + I_y2 = 20 times 150^3/12 + 150 times 20^3/12 = 5.72 times 10^6 I_y' = 5.72 times 10^6 mm^4